i am looking for the flow rate for a biasi m90e24s?

Have a look at page 14 of this document

http://www.biasi.co.uk/images/manuals/RIVA_COMPACT/INSTALLATION_USER/1908%20EDITION.pdf

Bill
June 2012

I found this statement...

"The flow rate for *all* the appliances in the house is limited by the capacity of the rising main. Flushing a toilet may thus lead to the hot water temperature fluctuating, or even going cold. Do not install a combination boiler unless your rising main is sufficiently good - flow rate may not be adequate for washing machines/dishwashers that require a hot feed."

At this place...

http://www.diyfaq.org.uk/plumbing/combi.html

Peccavi
April 2009